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When Facebook was founded on February 4, 2004, it defined
its mission as "Giving people the power to share and make the world more
open and connected."
With the widespread success of this social networking
website today more than 500 million
regular users as of April 2011 it may meet that goal for many.
When a Facebook user can no longer access an account, it can
be frustrating, but there is typically a reasonable explanation.Cookies/CacheFacebook suggests that any user who can't access their
account should clear cookies and cache on their computer as a first step.
This will help remove old and unneeded files from your
computer, and will sometimes help your computer to run faster, as well as
allowing access to Facebook again.
Once cookies and cache have been cleared, you should type
"m.facebook.com" into the address bar on your computer.
Avoid using any old bookmarks or links to visit Facebook for
this first visit after clearing the cookies and cache.Password Incorrect
If you attempt to log into your Facebook account with an
incorrect password, you will be unable to access your account.
Even if you have the correct email address, that is only
half of the log-in equation, and the correct password is absolutely necessary
to log into the site.
If you may have entered the wrong password, enter it again,
taking care to get each character correct.
Passwords are case sensitive, so all capital and lowercase
letters and any symbols must be entered correctly.

If you have forgotten your password, you will need to click
the "Forgot Your Password" link to recover your account and create a
new password.Account Closed
Facebook reserves the right to close accounts that they have
determined are in violation of their terms of service.
If Facebook found that your account contained inappropriate
content, did not represent a real person, or violated Facebook rules in some
way, the account may be closed, leaving you unable to access it.
If your account was closed for one of these reasons, your
login will fail and you will be provided with a link to Facebook's
"Confirm Your Identity" page, where you can read about typical
reasons for account closures.Email Login Incorrect
If you have entered the incorrect email address, you will be
unable to log into your Facebook account.
The email address that you use to log into Facebook is case
sensitive, just as your email address is. If you fail to capitalize a letter or
forget to insert an underscore that is part of the email address, login will
fail.
If you cannot access your Facebook account due to an
incorrect email address, double checking the address for correctness prior to
logging in again will resolve the issue.Compromised Account
If account information such as your email address or
password is stolen, your account may be compromised.
If, for example, your account information is stolen, the
person in possession of your log-in information can access your account and
change the password so that you will no longer be able to get to your account.
If you think this may have happened, you must access the
"Compromised Account" page on Facebook and follow steps to prove your
identity and secure your account.

When Facebook was founded on February 4, 2004, it defined
its mission as "Giving people the power to share and make the world more
open and connected."
With the widespread success of this social networking
website today more than 500 million
regular users as of April 2011 it may meet that goal for many.
When a Facebook user can no longer access an account, it can
be frustrating, but there is typically a reasonable explanation.Cookies/CacheFacebook suggests that any user who can't access their
account should clear cookies and cache on their computer as a first step.
This will help remove old and unneeded files from your
computer, and will sometimes help your computer to run faster, as well as
allowing access to Facebook again.
Once cookies and cache have been cleared, you should type
"m.facebook.com" into the address bar on your computer.
Avoid using any old bookmarks or links to visit Facebook for
this first visit after clearing the cookies and cache.Password Incorrect
If you attempt to log into your Facebook account with an
incorrect password, you will be unable to access your account.
Even if you have the correct email address, that is only
half of the log-in equation, and the correct password is absolutely necessary
to log into the site.
If you may have entered the wrong password, enter it again,
taking care to get each character correct.
Passwords are case sensitive, so all capital and lowercase
letters and any symbols must be entered correctly.
If you have forgotten your password, you will need to click
the "Forgot Your Password" link to recover your account and create a
new password.Account Closed
Facebook reserves the right to close accounts that they have
determined are in violation of their terms of service.
If Facebook found that your account contained inappropriate
content, did not represent a real person, or violated Facebook rules in some
way, the account may be closed, leaving you unable to access it.
If your account was closed for one of these reasons, your
login will fail and you will be provided with a link to Facebook's
"Confirm Your Identity" page, where you can read about typical
reasons for account closures.Email Login Incorrect
If you have entered the incorrect email address, you will be
unable to log into your Facebook account.
The email address that you use to log into Facebook is case
sensitive, just as your email address is. If you fail to capitalize a letter or
forget to insert an underscore that is part of the email address, login will
fail.
If you cannot access your Facebook account due to an
incorrect email address, double checking the address for correctness prior to
logging in again will resolve the issue.Compromised Account
If account information such as your email address or
password is stolen, your account may be compromised.
If, for example, your account information is stolen, the
person in possession of your log-in information can access your account and
change the password so that you will no longer be able to get to your account.
If you think this may have happened, you must access the
"Compromised Account" page on Facebook and follow steps to prove your
identity and secure your account.

Reset Facebook Password
Suddenly you attempt to login to your Facebook profile.
Perhaps you have simply forgotten your password or worst
case your Facebook account security has been compromised.
Having had this happen to me, I can help you reset your Facebook
password and restore your peace of mind.
You will be back networking with your friends, family and
coworkers in no time.
Go to your computer bring up the Facebook
login screen like you normally would.
Do not fill in any information.
Click on the link above your Facebook user
name and password that states forgot your password. This brings you to a
different screen.

Fill in the email address associated or on
file with your Facebook account.
If you cannot remember, keep trying different
email addresses until you do.
Click enter and a Facebook reset link will be
sent to your email so you can recover your password. It usually takes up to 5
minutes.
Check your spam email folder if the email does
not appear in your inbox.
Click the link in your email and answer any
security questions by Facebook.
This brings back to the Facebook website.
Reset your password with a phrase you will
remember mixed in with 1 to 2 numbers or more. Record this in a notebook or on
a safe place.
Use a different password than you would for
your email.
This decreases your chances of having both
websites compromised.

Assuming you are using Microsoft Internet Explorer, you have to do this:

In Internet Explorer, on the Tools menu, click Internet
Options.

Click the Privacy tab, and then click Advanced.

Click Override automatic cookie handling, and then specify how you
want Internet Explorer to handle cookies from first-party Web sites and
third-party Web sites (a Web site other than the one you are currently viewing).

To specify that you want Internet Explorer to always allow cookies to be
saved on your computer, click Accept.

To specify that you want Internet Explorer to never allow cookies to be
saved on your computer, click Block.

To specify that you want Internet Explorer to ask whether or not you want to
allow a cookie to be saved on your computer, click Prompt.

If you want Internet Explorer to always allow session cookies (cookies that
will be deleted from your computer when you close Internet Explorer) to be saved
on your computer, click Always allow session cookies.

Notes

Some Web sites require cookies; therefore, if you select a setting that does
not allow cookies to be saved on your computer, you might not be able to view
certain Web sites.

When you change your privacy settings, the changes might not affect cookies
that are already on your computer. If you want to ensure that all of the cookies
on your computer meet your privacy settings, you should delete all of the
existing cookies on your computer. When you return to Web sites that previously
had saved cookies on your computer, the Web sites that meet your privacy
settings will save cookies on your computer again. The Web sites that do not
meet your privacy settings will not be allowed to save cookies on your computer,
and might not function properly.